Drying oil



FILM HARDNESS Jan. 12, 1943. R. s. MORSE DRYING OIL Filed April 9, 1940 FIG. I.

TIME OF I 2 3 4 5 7 TIME OF REBODYING HOURS (250-270'6'.)

FIG. .5. 36

I2 8 RICHARD s. MORSE 4 INVENT OR g'roRgvEx s I0 20 4o f0 T/ME- HOURS Patented Jan. 12, 1943 DRYING OIL Richard S. Morse, Rochester, N. Y., assignor to Distillation Products, Inc., Rochester, N. Y., a corporation of Delaware Application April 9, 1940, Serial No. 328,702

7 Claims.

This invention relates to improved procedure for preparing superior bodied or polymerized oils for usein paints, varnishes, inks and the like.

Linseed oil has long been the accepted standard for superior drying oils. However, there has been considerable room for improvement as regards the drying time of linseed oil and theresistance'of the linseed oil films to weather resistance, abrasion, etc. Attempts have been made to prepare drying oils from fish oils, but the products have been usually quite unsatisfactory because of tackyness of the film, poor weather resistance, etc.

In Oosterhof Patent 2,065,728, December 29.

' 1936, and Fawcett 2,128,354, August 30, 1938, it

is proposed that bodied vegetable and animal drying oils be improved by subjecting them to high vacuum unobstructed path distillation to remove non-polymerizable materials therefrom. This procedure yields an undistilled residue which has markedly improved characteristics as regards drying time, film hardness, etc.

This invention has for its object to provide a method for preparing improved drying oils satisfactory for paints, varnishes and the like. Another object is to provide improved drying oils. Other objects are to improve the art. Further objects will become apparent from the following description and claims,

These and other objects are accomplished in accordance with my invention which includes subjecting a bodied oil to high vacuum unobstructed path distillation to remove volatiles or non-polymers .and then subjecting the imdistilled residue to a second bodying treatment. I have discovered that this rebodying of the undistilled residue reduces the drying time to a very short period of time and also increases film hardness, weather resistance and other desirable properties.

The bodied oil which is initially employed in my process, namely, that which is introduced into the still, is preferably bodied by heating to elevated temperature in the substantial absence of oxygen. Catalysts may be employed. Thisprocedure yields a bodied oil of high quality. However, other methods of bodying are well known in the art. 'Such methods comprise heating while in contact with oxygen, heating while in contact with catalysts. It is also possible to body oils by treatment with ultra-violet light, electric discharge, etc. My invention is applicable to bodied oils produced by any of these known methods.

The bodied oilcan be prepared by the bodying of vegetable or marine animal oils which contain polymerizable constituents. At the present time it is commercially unfeasible to polymerize oils having an iodine number below and for this reason I prefer to employ oils having an iodine number of at least 120. This is particularly true in the case of marine animal oils. Examples of oils which may be bodied and used in my invention are linseed, oiticica, soy, walnut, menhaden, sardine, and pilchard oils. The bodied oil is subjected to high vacuum un obstructed path distillation by heating it in a high vacuum and in a still so constructed. that the heated on is separated from the condensing surface by substantially unobstructed space. A pot type unobstructed space still can be employed. However, it is much better to employ a gravity flow type of high vacuum unobstructed path still in which the bodied oil is introduced onto the vaporizing surface and is caused to flow thereover in a thin film by gravity or liy forces 'greater than gravity, Gravity flow type of high vacuum stills are well known in the art and do not require further description. Greater than gravity fiow type high vacuum unobstructed path stills are described in Hickman application 99,631. In the preferred form. of such stills there is a rotatable vaporizing surface in the form of a disc which is adapted to be heated. A condensing surface is separated therefrom by unobstructed space. During operation the bodied oil is introduced onto the center of the rotating disc and is caused to flow thereover in the form of a'very thin film by centrifugal force. During such passage vaporization of non-polymerstakes place. I prefer to employ this type of still since it enables rapid distillation without decomposi tion.

The temperatures employed during the distillation will vary considerably depending upon the kind of oil treated and the type of still used. Temperatures of l50-300 C. are best used as far as economic considerations are concerned. Higher or lower temperatures can be used, but with lower temperatures the rate of distillation is uneconomically slow and with higher temperatures decomposition is a problem. Temperatures of about to 275 are preferred. Pressures greater than 2 mm. are usable but are not satisfactory because of increased decomposition. Pressures below about .1 mm. such as .01 to .0001 are best.

During the distillation non-polymers and nonpolymerizable materials are removed. There are wise removed and this is believed to materially contribute to thevalue of the subsequent rebodying treatment. The first bodying apparently is incomplete because of the presence of these materials. After their removal rebodying can be carried more nearly to completion yielding a superior product, While proportions involving up to 40% or even more can be removed as distillate, I have found that it is preferable to distill only to remove about 2-12% and particularly about Little improvement is obtained by removing amounts from 12-30%. A slight improvement takes place between and but I do not regard it as being sufficient to justify removal of more than 12%.

The undistilled residue is then subjected to a bodying treatment. The bodying may be any of the treatments described above in connection with the bodying of the original source material. However, I prefer to employ a bodying treatment which does not involve substantial oxidation and I particularly prefer to employ the conventional bodying treatment involving heating to an elevated temperature while in the presence of an inert gas or while under vacuum. This proce- This is particularly true in connection with re bodying by means of oxygen or oxidizing agents. The course of the rebodying can be easily followed by removal of samples and testing and when such tests indicate that the consistency of the oil is that desirable for the particular purpose in mind, the bodying treatment is terminated.

In the accompanying drawing I have graphically illustrated the beneficial results obtained by the procedureof my invention.

Referring to Fig. 1, in which drying time in minutes is plotted against time of rebodying in hours, it is shown that drying time of the un distilled residue is rapidly lessened by rebodying for a period'up to about six hours. Thereafter, little advantage is to be obtained by continued bodying. Fig. 1 also shows that the drying time of the undistilled residue can be reduced by approximately by a rebodying time of only one hour. Fig. 1 also illustrates the fact that the undistilled residue from 10% distillate has approximately the same drying time as undistilled residue from 30% distillate and that its characteristics in connection with rebodying are much the. same. Therefore, little advantage is to be obtained by removing more than 10 or 12% distillate. However, as remarked above, a slight increase takes place over 30% but does not seem to be sufiicient to warrant the added difliculties involved in the distillation.

' Fig. 2 illustrates the increase in film hardness by various periods of rebodyingin'hours in connection with an undistilled residue from a 10% distillate. It is seen that, as far as film hardness is concerned, the effect of rebodying reached a maximum at between two and three hours.

,The rebodying treatment in connection with the experiments illustrated in Figs. 1 and 2 involve treating the undistilled residues at .250- 270 C. in the presence of nitrogen.

.residue from a 10% distillate.

Referring to Fig. 3, it is seen that film hardness is plotted against time of drying or exposure to air in hours. Curve 13 illustrates the hardness as against time acquired by undistilled Curve C .shows the film hardness as against time of a residue from a 10% distillate which had been rebodied for one hour. Curve D shows the film hardness against time for. an undistilled residue from a 10% distillate which had been rebodied for three hours.

Example Menhaden oil was bodied by heating in the presence of nitrogen to 250-270 C. for about eight hours. The bodied product had the fol-' a temperature of 180 C. and maintained under a pressure of about .001 mm. 10% of the bodied oil was removed as distillate. The resulting undistilled residue was tested for drying time by mixing with a commercial drier and spreading on glass in a thin film of .001 mm. thickness which was maintained at room temperature and humidity. Finger smear tests were made every 15 minutes. The undistilled residue had a drying time of minutes as compared with min utes for the original bodied oil. The undistilled residue was rebodied by heating in a vacuum for 5 hours at 270 C. It was then mixed with a commercial drier and tested in the same way. It was found that the drying time had been reduced to 20 minutes. The film hardness had been correspondingly improved.

What I claim and desire to be secured by Letters Patent of the United States is:

l. The process which comprises subjecting a bodied oil to high vacuum unobstructed path distillation in order to remove a member of the group consisting of non-polymers, non-polymerizable materials and polymerization inhibitors and subjecting the undistilled residue to a second bodying treatment which is terminated before the oil loses its valuable paint characteristics.

2. The process which comprises subjecting a bodied oil to high vacuum unobstructed path distillation in order to remove a member of the group consisting of non-polymers, non-polymerizable materials, and polymerization inhibitors the amount removed being between 2 and 12% of the original oil and then subjecting the undistilled residue to a second bodying treatment which is terminated before the oil loses its valuable paint characteristics. a

3. The process of claim 1 in which the second bodying treatment is carried out at elevated temperature for a period of between 1 and 6 hours.

4. The process which comprises subjecting a bodied oil to high vacuum unobstructed path distillation in order to remove a member of the group consisting of non-polymers, non-polymerizable materials and polymerization inhibitors, and subjecting the undistilled residue to a second residue to an elevated temperature in the substantial absence of. oxygen for a period of about 1-5 hours.

5. The process which comprises subjecting a bodied fish oil having an iodine number above about 120 to high vacuum unobstructed path distillation in order to remove a member of the group consisting of non-polymers, non-polymerizable materials and polymerization inhibitors and then subjecting the undistilled residue to a second bodying treatment which is terminated before the oil loses its characteristics which make it satisfactory for use in paints and the like.

6. The process which comprises subjecting abodied fish oil having an iodine number above about 120 to high vacuum unobstructed path distillation in order to remove a member of the group consisting of non-polymers, non-polymerizable materials and polymerization inhibitors in amounts or not greater than about 10% and subjecting the undistilled residue to a second bodying treatment which is terminated before the residue loses its valuable paint characteristics.

"7. The process which comprises subjecting a bodied fish oil having an iodine number of above about 120 to high vacuum unobstructed path distillation in order to remove a member of the group consisting of non-polymers, non-polymerizable materials and polymerization inhibitors in amounts of about 10% and subjecting the undistilled residue to a bodying treatment involving heating to an elevated temperature for a period of less than about six hours.

' RICHARD s. MORSE. 

